The main objective of the proposed research is to measure and determine the physiologic importance of integrated concentrations and production rates of HGH and various other hormones. This will be accomplished using a technique newly developed specifically for this purpose. The integrated concentration of the hormone under consideration is measured in a pool of blood collected at a constant rate utilizing a small portable pump connected to a specially coated heparinized intravenous canula, that was developed by the investigators. The determination of the metabolic clearance rate simultaneously with determination of the integrated concentration will permit calculation of the blood production rate. In the first phase of the investigation, we have studied the relation of growth hormone (HGH) to normal and abnormal growth, and the effect of physiologic and pharmacologic stimulation on HGH clearance and production. This work will be further extended. In addition, the interrelationship of HGH, cortisol and insulin in obesity and diabetes is being investigated. Finally, the measurement of integrated plasma concentration and production rate of various other hormones (androgens, gonadotropins, aldosterone) will be determined using the same approach in physiologic and pathologic conditions.